E4OD soft/slipping 1-2 shift, slips in second, code 628, Updated
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E4OD soft/slipping 1-2 shift, slips in second, code 628, Updated
Hi all
I have a 1992 f150 5.8 E4OD 4x4 3.55, that is driving me nuts. It slips on the 1-2 shift under light throttle and slips in 2nd under light throttle in drive, if you Manuel shift it there is no slip.
If you step on it (more that ¼ throttle) it will go through the gears like a new truck, no slip!
If you Manuel shift it there is no slip, only in auto mode (gear selector in D), witch makes me think it is electrical and not mechanical.
It will also neutral out at a stop, give it a little gas, it will cache and away you go.
It dos not slip in 3rd or 4th gears and the tork locks up, (1900rps at 65 mph).
The only code is 628.
Things I have don so far.
Replaced MPLS with a known good unit (I now have backup lights).
Changed fluid an filter.
Checked TPS (.93V) and smooth through the range.
Inspected all wires.
Checked all fuses.
Check VSS (spedo works perfectly).
I am at my wits end and this thing has me stumped!
Any help will be greatly appreciated!
Thank you for your time!
Tom_Cat
I have a 1992 f150 5.8 E4OD 4x4 3.55, that is driving me nuts. It slips on the 1-2 shift under light throttle and slips in 2nd under light throttle in drive, if you Manuel shift it there is no slip.
If you step on it (more that ¼ throttle) it will go through the gears like a new truck, no slip!
If you Manuel shift it there is no slip, only in auto mode (gear selector in D), witch makes me think it is electrical and not mechanical.
It will also neutral out at a stop, give it a little gas, it will cache and away you go.
It dos not slip in 3rd or 4th gears and the tork locks up, (1900rps at 65 mph).
The only code is 628.
Things I have don so far.
Replaced MPLS with a known good unit (I now have backup lights).
Changed fluid an filter.
Checked TPS (.93V) and smooth through the range.
Inspected all wires.
Checked all fuses.
Check VSS (spedo works perfectly).
I am at my wits end and this thing has me stumped!
Any help will be greatly appreciated!
Thank you for your time!
Tom_Cat
Lead Driver
Joined: Jul 2007
Posts: 7,868
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From: Rhode Island
628 is excessive converter slip. Your symptoms sound like low fluid level, but you've said you changed the fluid.
It honestly sounds like a mechanical issue to me. It seems that at low throttle/low RPM, you're losing line pressure.
It honestly sounds like a mechanical issue to me. It seems that at low throttle/low RPM, you're losing line pressure.
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Low fluid was my thought to, but it is full. Bad epc solenoid?
What would cause low line pressure at low throttle/rpms, but not at higher throttle/rpms? I don't have a gage to check it with.
I am scared to drive it for fear I will burn it up!
Like I said if you punch it, it shifts just fine!
Please keep the thoughts coming, I need to get this fixed.
Thank you, Tom_Cat
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,709
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From: SE Florida
There is a problem with the intermediate clutch. When in manual 2 the intermediate band is applied, which takes much of the load off of the intermediate clutch. My guess is that the clutch is toast and the trans will need to be rebuilt.
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Well after checking and ohmed out all the solenoids (all check out good) I pulled the vss wires off the sensor and second gear worked like a charm!
Long story short, I traced the problem to the ECM, I removed the ECM and took the cover off and found two burned up capacitors!
Now I need to find a ecm, code# F2TF-12A650-CB and A2Z1
Anyone know what ECMs will interchange with it?
The reason I am fighting with it is I just bought it for $250 (one of them give me the cash and get it out of the yard deals)! The owner said it had “transmission troubles”.
Thank you for your time
Tom_Cat
Long story short, I traced the problem to the ECM, I removed the ECM and took the cover off and found two burned up capacitors!
Now I need to find a ecm, code# F2TF-12A650-CB and A2Z1
Anyone know what ECMs will interchange with it?
The reason I am fighting with it is I just bought it for $250 (one of them give me the cash and get it out of the yard deals)! The owner said it had “transmission troubles”.
Thank you for your time
Tom_Cat
Elder User
Joined: Jul 2011
Posts: 793
Likes: 2
From: Vernon, BC
Can you replace just the capacitors? Many on here have (I haven't as I have had no problems with my ECM yet). If you can't or don't want to tackle the problem then replace your current ECM with one of the same colour. Try to get one that has the same engine and transmission combination although I also think one from a 302 and E4OD would also work. Hopefully some others on here with more experience than I have will chime in.
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Can you replace just the capacitors? Many on here have
Can you enplane father, do the capacitors affect shifting?
Can you enplane father, do the capacitors affect shifting?
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Update
I replaced all the caps in the computer, no change. It still slips in second under light throttle, punch it and it grabs.
Disconnect the vss and it grabs second real good (no slip at all)!
Took it for a 50 mi test run (vss disconnected) and it never missed a beat. Only code is for vss and the tork doesn't lock with the vss unhooked.
Mark K, I don't think the intermediate clutches are burned up, it grabs to good with the vss unhooked. What else do you think it could be?
Lead Head, it is indeed acting like low line pressure.
Please keep the thoughts coming, I can use all the help I can get.
The epc solenoid ohms out at 5.23 ohms, can it still pass the ohm test but be bad?
Thank you for your time
Tom_Cat
I replaced all the caps in the computer, no change. It still slips in second under light throttle, punch it and it grabs.
Disconnect the vss and it grabs second real good (no slip at all)!
Took it for a 50 mi test run (vss disconnected) and it never missed a beat. Only code is for vss and the tork doesn't lock with the vss unhooked.
Mark K, I don't think the intermediate clutches are burned up, it grabs to good with the vss unhooked. What else do you think it could be?
Lead Head, it is indeed acting like low line pressure.
Please keep the thoughts coming, I can use all the help I can get.
The epc solenoid ohms out at 5.23 ohms, can it still pass the ohm test but be bad?
Thank you for your time
Tom_Cat
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
You could have some internal fluid leak, or still weak clutches. With the VSS unplugged, it likely goes into limp mode and forces maximum line pressure.
I do know the early E4OD had line-pressure issues once the pump started to get worn. I would hook up a pressure gauge to see what's going on.
I do know the early E4OD had line-pressure issues once the pump started to get worn. I would hook up a pressure gauge to see what's going on.
Posting Guru
Joined: May 2010
Posts: 1,146
Likes: 17
From: Central Indiana
Although I'm not as familiar with the E4OD as Mark Kovalski, I am pretty sure when you punch it to the floor, the transmission operates at a higher line pressure to keep the clutches from slipping.
What is probably happening is you're getting just enough line pressure when punched to keep it from slipping, versus just cruising around at a lower line pressure.
I could be wrong but I would expect Mark K. will jump in and correct me on this. When I taught transmissions, the AOD, TH-700 and Ford ATX transaxle were the newest things we taught.
What is probably happening is you're getting just enough line pressure when punched to keep it from slipping, versus just cruising around at a lower line pressure.
I could be wrong but I would expect Mark K. will jump in and correct me on this. When I taught transmissions, the AOD, TH-700 and Ford ATX transaxle were the newest things we taught.
Senior User
Joined: Mar 2015
Posts: 450
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From: Merchantville, NJ 08109
You could also very well have damaged springs in the valve body- In the midst of my transmission teardown, I just took the valve bodies apart, and the springs in the accumulator body on all three accumulator pistons were messed up- One of the smallest springs had a definite curve to it- the other two were broken to bits- one of them looked almost like chain mail, and it was intertwined with the outer spring! Happily, I am already set up with a TransGo "Tugger" kit, so already planned to replace the springs... You may wish to check into that.
Scott
Scott
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Update
I added a 10 ohm 20 watt resistor to the epc circuit and now second gear is grabbing good and it doesn't fall out of drive at a stop. Now there is no slip and it dos not take for ever to cache drive (use to take about 5 to 7 seconds to engage drive when shifted from reverse).
In the mean time I am looking for a post 95 unit to rebuild and replace this transmission with.
I will run this trans tell it blows then replace it with the post 95 unit.
For $250 I don't think I made a bad deal! Rest of the truck is in good shape and the rubber is new!
I want to thank everyone for there input and advice.
Tom_Cat
I added a 10 ohm 20 watt resistor to the epc circuit and now second gear is grabbing good and it doesn't fall out of drive at a stop. Now there is no slip and it dos not take for ever to cache drive (use to take about 5 to 7 seconds to engage drive when shifted from reverse).
In the mean time I am looking for a post 95 unit to rebuild and replace this transmission with.
I will run this trans tell it blows then replace it with the post 95 unit.
For $250 I don't think I made a bad deal! Rest of the truck is in good shape and the rubber is new!
I want to thank everyone for there input and advice.
Tom_Cat